Analysis of environmental driving mechanisms for vertical surface deformation in the permafrost section of the Qinghai-Tibet engineering corridor, China

Permafrost in the Qinghai-Tibet Plateau is highly susceptible due to thawing and degradation under the climate warming and extreme warming events, which can trigger surface subsidence and uplift phenomena. This study investigates the vertical surface deformation along the Qinghai-Tibet Engineering Corridor (QTEC) based on the dataset derived from interferometric synthetic aperture radar (InSAR) processing of the ascending and descending Sentinel-1 datasets. Using the geographical detector method, 24 potential factors influencing deformation was selected, including climatic, topographic, soil, hydrological, vegetation index, and cryospheric indicators to explore the driving mechanisms according to the q-value of factor detection processing. Results indicate that climatic factors (mean annual temperature and precipitation) and permafrost-related parameters (surface frost number, freezing index, thawing index) are the primary drivers of vertical deformation, with the q-value greater than 0.095. Topographic parameters (latitude, elevation, topographic relief, slope, longitude) also significantly influence deformation with the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>q</mml:mi> </mml:math> -value between 0.054 and 0.086, followed by the east-west deformation rate and soil organic matter content with the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>q</mml:mi> </mml:math> -value at 0.052, while other factors with the q-value less than 0.05. This study elucidates the intrinsic mechanisms driving surface subsidence and uplift along the QTEC, providing a theoretical foundation for the construction of future infrastructure projects and the maintenance of existing engineering facilities in permafrost regions.